I need to set conditional formatting to a field that is one color when entered the first time on that record and when the record is revisited the next day or any other day after that the text needs to change color only on the newly entered text leaving the original text color alone. I have been unsuccessful with "Value Is" options.

Have you considered entering the text in a related table (e.g. "Notes")? That way, each note could have a timestamp and the user name auto-entered, and it would be easy to distinguish what happened when.